This invention relates to a starter strip for use in installing horizontally elongated siding panels such as are mounted in overlapping parallel courses on an exterior building wall to provide a protective and attractive covering for the wall.
In one known type of horizontal siding panel, with which the presennt invention is particularly concerned, the bottom margin of each panel is bent inwardly and then upwardly to form an inwardly projecting, upwardly opening longitudinal channel flange or butt flange with an upstanding inner leg, and the top marginal portion of the panel is shaped to provide an outwardly and downwardly projecting longitudinal lip. As installed on a wall in overlapping array, the panels of each course are secured to the wall at their top margins, e.g. by gasteners such as nails driven through a nailing flange portion of the panel top margin above the lip; the butt flanges of the panels of each course (except the lowermost course) overlap the top margin of the next lower source of panels, concealing the fasteners of the lower course, and receive and interlockingly engage the lips of the lower-course panels so that every panel is effectively anchored to the wall along both top and bottom margins. Since the butt flange of each panel holds the panel lower margin away from the wall, the exposed (outwardly facing) major surfaces of the panels slope downwardly and outwardly, simulating the appearance of conventional wooden clapboards or rows of shingles. These panels, commonly roll-formed from sheet metal (e.g. aluminum) strip or molded of plastic (e.g. vinyl), may be eight inches or more in vertical height and as much as twelve feet or more in horizontal length.
Installation of panels of the described type on a wall involves mounting progressively higher courses in succession, one above another, the butt flanges of each higher course being interlocked with the lips of the already-mounted next lower course before the top margins of the higher-course panels are nailed to the wall. The panels of the lowermost course (which are mounted first), however, have no subjacent panel lips with which to interlock. Accordingly, it is customary to mount a so-called starter strip along the bottom of the wall (prior to installing the panels) for anchoring the butt flanges of the lowermost course of panels, thereby to prevent undesired displacement of the bottom margins of these panels. Typically, the starter strip is a horizontally elongated, roll-formed sheet metal (or molded plastic) member, having an upper longitudinal portion which lies flat against and is nailed to the wall, and a lower longitudinal portion shaped to be received within, and interlockingly engaged by, the butt flanges of the lowermost course of panels, which overlap and conceal the starter strip when the panels are installed. This lower portion of the starter strip may be disposed at, or may project below, the bottom of the wall, depending on the level at which it is desired to position the bottom margin of the panel array relative to the wall.
Conventional starter strips, as heretofore used, have had various disadvantages. Commonly, they are so designed that the panel butt flanges engage them only loosely; thus the panels tend to rattle undesirably against the starter strip, especially when the starter strip projects below the bottom edge of a wall, and in some cases the panels may even become disengaged from the starter strip as a result of thermal changes or settling of the building on which they are mounted. In addition, installation of the lowermost course of panels is difficult, because the loosely engaged starter strip does not maintain the panels in position for nailing their top margins, and the instaler must accordingly hold in place a panel that may be many feet in length while performing the nailing operation. It would be beneficial to provide a starter strip that firmly and securely holds the panel butt flanges that engage it; however, known types of starter strips shaped and dimensioned to be snugly received within the butt flange of a panel require impracticably close manufacturing tolerances, do not permit lateral movement of the panels or accommdoate thermal expansion and contraction, are not capable of use with panels of different butt widths, and present problems for the instaler in that it has been difficult to insert the butt flange of a panel properly under and around the starter strip.